The fatty acids found in MCTs are called medium-chain fatty acids (MCFAs). Like all triglycerides, MCTs are composed of a glycerol backbone and three fatty acids. In the case of MCTs, 2 or 3 of the fatty acid chains attached to glycerol are of medium length.

Molecular weight analysis[3] of milk from different species showed that while milk fats from all studied species were primarily composed of long-chain fatty acid (16 and 18 carbons long), approximately 10–20% of the fatty acids in milk from horses, cows, sheep, and goats were medium-chain fatty acids.

Some studies have shown that MCTs can help in the process of excess calorie burning, thus weight loss.[4][5][6][7][8] MCTs are also seen as promoting fat oxidation and reduced food intake.[9] Interest in MCTs has been expressed by endurance athletes and the bodybuilding community.[10] While health benefits from MCTs seem to occur, a link to improved exercise performance is weak.[9] A number of studies back the use of MCT oil as a weight loss supplement, but these claims are not without conflict, as about an equal number found inconclusive results.[11]

Medium-chain triglycerides are generally considered a good biologically inert source of energy that the human body finds reasonably easy to metabolize. They have potentially beneficial attributes in protein metabolism, but may be contraindicated in some situations due to a reported tendency to induce ketogenesis and metabolic acidosis.[12] However, there is other authority reporting no risk of ketoacidosis or ketonemia with MCTs at levels associated with normal consumption.[13]

Due to their ability to be absorbed rapidly by the body, medium-chain triglycerides have found use in the treatment of a variety of malabsorption ailments. MCT supplementation with a low-fat diet has been described as the cornerstone of treatment for Waldmann disease.[14] MCTs are an ingredient in some specialised parenteral nutritional emulsions in some countries.[15][16] Studies have also shown promising results for epilepsy through the use of ketogenic dieting.[17][18] Select studies have shown promising results for neurodegenerative disorders (e.g. Alzheimer's and Parkinson's diseases)[19] but clinical effectiveness is not yet established.

MCTs are bland compared to other fats and do not generate off-notes (dissonant tastes) as quickly as LCTs. They are also more polar than LCTs. Because of these attributes, they are widely used as solvents for flavours and oral medicines and vitamins.[20]